cascading python executions only if return code is 0

[Roy Smith]

In article <mailman.4645.1388111765.18130.python-list at python.org>,
 Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Dec 27, 2013 at 1:20 PM, Dennis Lee Bieber
> <wlfraed at ix.netcom.com> wrote:
> > On Fri, 27 Dec 2013 12:44:35 +1100, Chris Angelico <rosuav at gmail.com>
> > declaimed the following:
> >
> >>On Fri, Dec 27, 2013 at 12:37 PM, Roy Smith <roy at panix.com> wrote:
> >>> How about this one, that I wrote yesterday;
> >>>
> >>>         assert second >= self.current_second, "time went backwards"
> >>>
> >>> I think that's pretty high up on the "can never happen" list.
> >>
> >>assert second >= self.current_second, "user changed the clock"
> >>
> >         Why blame the user if an NTP synch made the adjustment? <G>
> 
> True, it could have been NTP, or maybe the original assert was right
> and we're on the other side of an event horizon. But it's much more
> fun to blame the user.
> 
> ChrisA

NTP is never supposed to move the clock backwards.  If your system clock 
is fast, it's supposed to reduce the rate your clock runs until it's 
back in sync.  Well, maybe it only does that for small corrections?